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RF Direction Finder — Parallax Forums

RF Direction Finder

ArchiverArchiver Posts: 46,084
edited 2003-03-04 22:49 in General Discussion
I have a young that often wonders off in larger stores.
No flames about parenting please. I'm thinking of a project build a small
RF transmitter that I can use to track him down. I would like to be able to
determine the direction of the signal. I could use that to head in the
right direction and cut down on the search time.

I could also use it on my wife. Or she might use it on me.
I think close range couple of hundred feet.

Would RF receivers output a raw signal level so I can use some type of a/d
conversion.
Suggestion Please


Original Message
From: Dwayne Reid [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=B-jWfuaTkDUmm8iMpazZ4FLEJ0N7RVs2rtRmbVDk60q-SzCHwHc-GcdlfOrEG63ysVvQ--OFrfrN-8bx3SB8]dwayner@p...[/url
Sent: Thursday, February 27, 2003 4:43 PM
To: basicstamps@yahoogroups.com
Subject: Re: [noparse][[/noparse]basicstamps] Water pipe pin hole problem

At 01:12 PM 2/27/03 -0800, Tracy Allen wrote:
>Hi Leroy,
>
>Bob Pease in Electronics Design magazine (I think it was he, there)
>had an article about the process of troubleshooting as exemplified by
>a water leak he had to track down in the roof of his house.
>Troubleshooting is one of those things that crosses topical
>boundaries.
>
>Bob's article archive:
> http://www.elecdesign.com/Index.cfm?Action=Pease
>
>I don't know which article it was, but Bob's articles are always a
>good read for electronics and beyond.

This one, I think.

<http://www.elecdesign.com/Articles/Index.cfm?ArticleID=5910>

dwayne

--
Dwayne Reid <dwayner@p...>
Trinity Electronics Systems Ltd Edmonton, AB, CANADA
(780) 489-3199 voice (780) 487-6397 fax

Celebrating 19 years of Engineering Innovation (1984 - 2003)
.-. .-. .-. .-. .-. .-. .-. .-. .-. .-
`-' `-' `-' `-' `-' `-' `-' `-' `-'
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[noparse][[/noparse]Non-text portions of this message have been removed]

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2003-03-03 18:05
    The Doppler rfdf works great, though it is rather complicated. Look for
    direction finding or fox hunting in the Amateur Radio areas of the web.
    There are companies that make the doppler units, and you can build a
    simple unit yourself. Problem is that the overall situation is somewhat
    large and clunky. Possibly suggestion would be the GMRS or FRS radios
    which are sort of cheap. Small, neat, something the youngster would
    love to use, and the wife could fit in the purse<G>.

    Original Message
    From: Sadler Porter [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=KKI7TnGExzjerIxRZhpQLUM_rb5PX5_m7ScB5RhQcsvuTDvFWCMB1qoD33wJzvjyHIc4G6EQ8JnbOUDN6MxZ5g]porter.sadler@s...[/url
    Sent: Monday, March 03, 2003 12:32 PM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] RF Direction Finder


    I have a young that often wonders off in larger stores.
    No flames about parenting please. I'm thinking of a project build a
    small
    RF transmitter that I can use to track him down. I would like to be
    able to determine the direction of the signal. I could use that to head
    in the right direction and cut down on the search time.

    I could also use it on my wife. Or she might use it on me.
    I think close range couple of hundred feet.

    Would RF receivers output a raw signal level so I can use some type of
    a/d conversion. Suggestion Please


    Original Message
    From: Dwayne Reid [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=Gsxm4Kg-jm6r5zXdwqkDcJaQr44gZqXolMnwHjNQuk-tFFxpiErwz89j5ON_EqTV9YKpHQwnHzv6EDPbGq8]dwayner@p...[/url
    Sent: Thursday, February 27, 2003 4:43 PM
    To: basicstamps@yahoogroups.com
    Subject: Re: [noparse][[/noparse]basicstamps] Water pipe pin hole problem

    At 01:12 PM 2/27/03 -0800, Tracy Allen wrote:
    >Hi Leroy,
    >
    >Bob Pease in Electronics Design magazine (I think it was he, there) had

    >an article about the process of troubleshooting as exemplified by a
    >water leak he had to track down in the roof of his house.
    >Troubleshooting is one of those things that crosses topical boundaries.
    >
    >Bob's article archive:
    > http://www.elecdesign.com/Index.cfm?Action=Pease
    >
    >I don't know which article it was, but Bob's articles are always a good

    >read for electronics and beyond.

    This one, I think.

    <http://www.elecdesign.com/Articles/Index.cfm?ArticleID=5910>

    dwayne

    --
    Dwayne Reid <dwayner@p...>
    Trinity Electronics Systems Ltd Edmonton, AB, CANADA
    (780) 489-3199 voice (780) 487-6397 fax

    Celebrating 19 years of Engineering Innovation (1984 - 2003)
    .-. .-. .-. .-. .-. .-. .-. .-. .-. .-
    `-' `-' `-' `-' `-' `-' `-' `-' `-'
    Do NOT send unsolicited commercial email to this email address. This
    message neither grants consent to receive unsolicited commercial email
    nor is intended to solicit commercial email.


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    basicstamps-unsubscribe@yahoogroups.com
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    [noparse][[/noparse]Non-text portions of this message have been removed]


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  • ArchiverArchiver Posts: 46,084
    edited 2003-03-03 19:16
    > I have a young that often wonders off in larger stores.
    > No flames about parenting please. I'm thinking of a project build a small
    > RF transmitter that I can use to track him down. I would like to be able to
    > determine the direction of the signal. I could use that to head in the
    > right direction and cut down on the search time.
    >
    > I could also use it on my wife. Or she might use it on me.
    > I think close range couple of hundred feet.
    >
    > Would RF receivers output a raw signal level so I can use some type of a/d
    > conversion.

    A store environment with all the metal shelves is going to be a big
    problem.

    I would suggest a leash -they make them especailly for kids. If that
    it too cumbersome, perhaps an RF proximity alarm whereby if the
    child is more than 15 feet away, an alarm sounds so you can find
    him/her before they get too far.

    Mark Hillier, VE6HVW
    President, HVW Technologies Inc.
    Canadian Distributors of Parallax Products and other Neat Stuff
    Tel: (403)-730-8603 Fax: (403)-730-8903
    http://www.HVWTech.com
    ** New Breadboard Voltage Regulator (BVR) -A plugable +5 Volt
    power supply !
  • ArchiverArchiver Posts: 46,084
    edited 2003-03-03 23:56
    Shocking dog collar. Just zero in on the scream. <grin>

    Actually, they have / had a deal for luggage that would beep if you got to
    far from it, either accidentally or if someone walked off with it. Might
    check the junk catalogs like Sharper Image, Brookstone or similar.

    To track down an RF signal triangulation and multiple receivers, you need a
    directional antenna with more gain in one direction. You can do it with a
    simple dipole, but without additional elements you will see the same signal
    strength facing towards or away from the source.

    Original Message

    > I have a young that often wonders off in larger stores.
    > No flames about parenting please. I'm thinking of a project build a small
    > RF transmitter that I can use to track him down. I would like to be able
    to
    > determine the direction of the signal. I could use that to head in the
    > right direction and cut down on the search time.
    >
    > I could also use it on my wife. Or she might use it on me.
    > I think close range couple of hundred feet.
    >
    > Would RF receivers output a raw signal level so I can use some type of a/d
    > conversion.
    > Suggestion Please
  • ArchiverArchiver Posts: 46,084
    edited 2003-03-03 23:57
    Radio Shack had some kid-friendly FRS radios on closeout for $10. They look
    like a big ladybug and the wings spread open to access the radio.


    Original Message

    > The Doppler rfdf works great, though it is rather complicated. Look for
    > direction finding or fox hunting in the Amateur Radio areas of the web.
    > There are companies that make the doppler units, and you can build a
    > simple unit yourself. Problem is that the overall situation is somewhat
    > large and clunky. Possibly suggestion would be the GMRS or FRS radios
    > which are sort of cheap. Small, neat, something the youngster would
    > love to use, and the wife could fit in the purse<G>.

    > I have a young that often wonders off in larger stores.
    > No flames about parenting please. I'm thinking of a project build a
    > small
    > RF transmitter that I can use to track him down. I would like to be
    > able to determine the direction of the signal. I could use that to head
    > in the right direction and cut down on the search time.
    >
    > I could also use it on my wife. Or she might use it on me.
    > I think close range couple of hundred feet.
    >
    > Would RF receivers output a raw signal level so I can use some type of
    > a/d conversion. Suggestion Please
  • ArchiverArchiver Posts: 46,084
    edited 2003-03-04 00:08
    Sadler,

    Well, no-one else is jumping in, so I'll give it a shot. All this is based
    on finding model airplanes and rockets when I was a kid, so I don't know
    what cool new devices are out there for this.

    You can have a system based on the strength of the signal. This isn't very
    good on moving targets, and doesn't show you which direction immediately.
    You have to walk with the receiver to determine direction and can get fooled
    by signal reflections and general weirdness.

    Another way is to have a tuned directional antenna on the receiver. Easily
    made and excellent for this purpose is a loop antenna. Very directional, so
    you know which direction to start walking. The thing is, these can be a pain
    to tune, as the antenna must be in very close tune to the frequency you are
    using. This requires a 'scope to do well, although calculations and testing
    can yield good results, it just takes patience. I am currently struggling
    with building a loop antenna for very low frequencies (60kHz).

    Of course, even better is combining the two, checking both signal strength
    and using a directional antenna.

    Anyway, I would start by looking for a simple low power AM radio transmitter
    schematic. There are loads on the web. Make that, and then you can use a
    cheap portable AM radio as the basis of your receiver. Construct a loop
    antenna and substitute it for the ferrite loopstick inside the receiver.
    There is a lot of loop antenna information out there, and you could also buy
    one.

    If you want to get a stamp involved, then you could have a display of LEDs
    and/or a tone that showed direction and proximity.

    Hope this helps,

    Jonathan

    www.madlabs.info

    Original Message
    From: "Sadler Porter" <porter.sadler@s...>
    To: <basicstamps@yahoogroups.com>
    Sent: Monday, March 03, 2003 9:32 AM
    Subject: [noparse][[/noparse]basicstamps] RF Direction Finder


    > I have a young that often wonders off in larger stores.
    > No flames about parenting please. I'm thinking of a project build a small
    > RF transmitter that I can use to track him down. I would like to be able
    to
    > determine the direction of the signal. I could use that to head in the
    > right direction and cut down on the search time.
    >
    > I could also use it on my wife. Or she might use it on me.
    > I think close range couple of hundred feet.
    >
    > Would RF receivers output a raw signal level so I can use some type of a/d
    > conversion.
    > Suggestion Please
    >
    >
    >
    Original Message
    > From: Dwayne Reid [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=V-bhFD3_Gyre0KBuzEHml0jtXPIYHHykYMVdaYCePJtXKhHfqsJCRwCTz116eQ4QgBcqm6Dpyp-ybhibFLXn]dwayner@p...[/url
    > Sent: Thursday, February 27, 2003 4:43 PM
    > To: basicstamps@yahoogroups.com
    > Subject: Re: [noparse][[/noparse]basicstamps] Water pipe pin hole problem
    >
    > At 01:12 PM 2/27/03 -0800, Tracy Allen wrote:
    > >Hi Leroy,
    > >
    > >Bob Pease in Electronics Design magazine (I think it was he, there)
    > >had an article about the process of troubleshooting as exemplified by
    > >a water leak he had to track down in the roof of his house.
    > >Troubleshooting is one of those things that crosses topical
    > >boundaries.
    > >
    > >Bob's article archive:
    > > http://www.elecdesign.com/Index.cfm?Action=Pease
    > >
    > >I don't know which article it was, but Bob's articles are always a
    > >good read for electronics and beyond.
    >
    > This one, I think.
    >
    > <http://www.elecdesign.com/Articles/Index.cfm?ArticleID=5910>
    >
    > dwayne
    >
    > --
    > Dwayne Reid <dwayner@p...>
    > Trinity Electronics Systems Ltd Edmonton, AB, CANADA
    > (780) 489-3199 voice (780) 487-6397 fax
    >
    > Celebrating 19 years of Engineering Innovation (1984 - 2003)
    > .-. .-. .-. .-. .-. .-. .-. .-. .-. .-
    > `-' `-' `-' `-' `-' `-' `-' `-' `-'
    > Do NOT send unsolicited commercial email to this email address.
    > This message neither grants consent to receive unsolicited
    > commercial email nor is intended to solicit commercial email.
    >
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed. Text in the Subject and
    > Body of the message will be ignored.
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
    >
    >
    > [noparse][[/noparse]Non-text portions of this message have been removed]
    >
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed. Text in the Subject and
    Body of the message will be ignored.
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2003-03-04 01:13
    Sadler,
    I was thinking about how you could find you kid when he gets away from
    you. First of all I thought that you could put a remote M80 on his
    back and when he gets away just detonate that should be able to hear
    the Loud bang and see the flash when it goes but lets be logical here
    some crack origination would not like that (the same people that think
    jails should be 5 star hotels). Anyways, I though of something with a
    modified dog collar but those things most decently cause brain damage
    (I had a little to much fun shocking my dog when I was a kid now he is
    fairly messed up. All though that might have the antifreeze I gave him
    when there was a drought.)
    I have it, safe but expensive. First you have a GPS unit mounted with
    an interface to a BS2SX after that you have the BS2SX interfaced with a
    modem that is connected to a cell phone. Then you have BS2SX
    interfaced with one of those modules that can play audio files and you
    download numbers 0 through 9 into it. So I bet you wondering how this
    is going to work out. First you will dial into the cell phone from
    another cell phone and the BS2SX will answer the phone and then
    transmit the GPS location audibly to your cell phone. BINGO! Just like
    that you know where the kid is. Type the location into another GPS
    unit then it will take you to your kid.

    PS If this crazy invention works save for when the kid becomes a teen
    may come in handy.

    Hope no one uses my input.
    Richey
  • ArchiverArchiver Posts: 46,084
    edited 2003-03-04 16:12
    Sadler et al

    i don't remember the source but someone has or is comming out with a
    frs radio with gps built in and will immediatly show where its twin
    is, direction and how far.

    I want to think it is garmin but not sure. That is the best answer to
    your problem as the range should be much better than the stolen
    luggage alarm which is less than 100 feet and does nothing to tell
    you
    which way and how far.

    73
    spence
  • ArchiverArchiver Posts: 46,084
    edited 2003-03-04 16:34
    I think you are referring to the Garmin Rino
    ....http://www.garmin.com/products/rino120/....


    --Aaron

    Original Message
    From: k4kep <k4kep@b...> [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=QnFGPWlihAOoYMzF38_nvmRW9eOaOLcp8c2A2V_TX6nDMefYG0QXrj9KqNjr7J25YK4BA_HzhUD7zfMiYfo]k4kep@b...[/url
    Sent: Tuesday, March 04, 2003 8:12 AM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] RE: RF Direction Finder


    SADLER ET AL

    I DON'T REMEMBER THE SOURCE BUT SOMEONE HAS OR IS COMMING OUT WITH A
    FRS RADIO WITH GPS BUILT IN AND WILL IMMEDIATLY SHOW WHERE ITS TWIN
    IS, DIRECTION AND HOW FAR.

    I WANT TO THINK IT IS GARMIN BUT NOT SURE. THAT IS THE BEST ANSWER TO
    YOUR PROBLEM AS THE RANGE SHOULD BE MUCH BETTER THAN THE STOLEN
    LUGGAGE ALARM WHICH IS LESS THAN 100 FEET AND DOES NOTHING TO TELL YOU
    WHICH WAY AND HOW FAR.

    73
    SPENCE


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  • ArchiverArchiver Posts: 46,084
    edited 2003-03-04 19:15
    Luggage LoJack?
    Original Message
    From: <k4kep@b...>
    To: <basicstamps@yahoogroups.com>
    Sent: Tuesday, March 04, 2003 11:12 AM
    Subject: [noparse][[/noparse]basicstamps] RE: RF Direction Finder


    > SADLER ET AL
    >
    > I DON'T REMEMBER THE SOURCE BUT SOMEONE HAS OR IS COMMING OUT WITH A
    > FRS RADIO WITH GPS BUILT IN AND WILL IMMEDIATLY SHOW WHERE ITS TWIN
    > IS, DIRECTION AND HOW FAR.
    >
    > I WANT TO THINK IT IS GARMIN BUT NOT SURE. THAT IS THE BEST ANSWER TO
    > YOUR PROBLEM AS THE RANGE SHOULD BE MUCH BETTER THAN THE STOLEN
    > LUGGAGE ALARM WHICH IS LESS THAN 100 FEET AND DOES NOTHING TO TELL
    > YOU
    > WHICH WAY AND HOW FAR.
    >
    > 73
    > SPENCE
    >
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed. Text in the Subject and
    Body of the message will be ignored.
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2003-03-04 22:03
    I think you might be refering to the: GPS Garmin Rino 120
    Link follows: http://www.garmin.com/products/rino120/
    I do not work for this company, Nor do I Endorse this Product.
    I personaly think this looks like a great product for what you are
    describing, however, I think downside is 2 mile voice range and maybe your
    pocketbook. Someone will eventually increase the range or put the
    capabilities into a cellualr phone .... I'll bet.

    Original Message
    From: "Tim Weaver" <tweaver@i...>
    To: <basicstamps@yahoogroups.com>
    Sent: Tuesday, March 04, 2003 12:15 PM
    Subject: Re: [noparse][[/noparse]basicstamps] RE: RF Direction Finder


    > Luggage LoJack?
    >
    Original Message
    > From: <k4kep@b...>
    > To: <basicstamps@yahoogroups.com>
    > Sent: Tuesday, March 04, 2003 11:12 AM
    > Subject: [noparse][[/noparse]basicstamps] RE: RF Direction Finder
    >
    >
    > > SADLER ET AL
    > >
    > > I DON'T REMEMBER THE SOURCE BUT SOMEONE HAS OR IS COMMING OUT WITH A
    > > FRS RADIO WITH GPS BUILT IN AND WILL IMMEDIATLY SHOW WHERE ITS TWIN
    > > IS, DIRECTION AND HOW FAR.
    > >
    > > I WANT TO THINK IT IS GARMIN BUT NOT SURE. THAT IS THE BEST ANSWER TO
    > > YOUR PROBLEM AS THE RANGE SHOULD BE MUCH BETTER THAN THE STOLEN
    > > LUGGAGE ALARM WHICH IS LESS THAN 100 FEET AND DOES NOTHING TO TELL
    > > YOU
    > > WHICH WAY AND HOW FAR.
    > >
    > > 73
    > > SPENCE
    > >
    > >
    > > To UNSUBSCRIBE, just send mail to:
    > > basicstamps-unsubscribe@yahoogroups.com
    > > from the same email address that you subscribed. Text in the Subject
    and
    > Body of the message will be ignored.
    > >
    > >
    > > Your use of Yahoo! Groups is subject to
    http://docs.yahoo.com/info/terms/
    > >
    > >
    >
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
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    >
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2003-03-04 22:49
    I believe it is the Garmin Rhino, and its already available. However, GPS
    does not work well or at all in doors.

    Original Message

    > I DON'T REMEMBER THE SOURCE BUT SOMEONE HAS OR IS COMMING OUT WITH A
    > FRS RADIO WITH GPS BUILT IN AND WILL IMMEDIATLY SHOW WHERE ITS TWIN
    > IS, DIRECTION AND HOW FAR.
    >
    > I WANT TO THINK IT IS GARMIN BUT NOT SURE. THAT IS THE BEST ANSWER TO
    > YOUR PROBLEM AS THE RANGE SHOULD BE MUCH BETTER THAN THE STOLEN
    > LUGGAGE ALARM WHICH IS LESS THAN 100 FEET AND DOES NOTHING TO TELL
    > YOU
    > WHICH WAY AND HOW FAR.
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